Pneumatic insert for shoes



June 22, 1937. H. VOGEL PNEUMATIC INSERT FOR SHOES Filed Dec. 24, 1935 -Patented June 22, v

. 2,084,517 r I PNEUMATIC INSERT FOR SHOES. "Hans Vogel, Frankfort-on-the-Main, Germany "Application December 24, 1935, Serial No. 56,029 In Germany-February 19, 1935 Claims. (Cl. 36-71 'I'hislinvention relates to a pneumatic shoe insert or arch support oi the low-pressure-type.

Numerouspneumatic shoe inserts or arch supports have ,alreadybecome known but have all proved unsatisfactory. The invention solves for the first timethe problem of producing a pneu- 'matic shoe insert or arch support which really satisflesall the requirements.

7 M There are several kinds of pneumatic shoe in- 1 sertsor arch supports, such as thosehaving a pneumatic padadapted to theshapeof the arch of the foot andthose comprising a rubber bag the hollow space of which extends over the heel and the ball. The shoe inserts of the -.flrstmentioned type are generallyhigh-pressure shoe inserts, i. e. inserts in which the'pressure is so 1 high that the pneumaticpad cannot be compressed considerably under the influence of the weight restinglupon the same, and therefore sup-.

ports the arch of the foot. "The operation of such shoe inserts or arch supports is substantially the same asthat of rigid shoe inserts, as the foot is supported both duringwalking and when at rest. I g

' .,pressure being exerted upwards against, so as to In pneumatic shoe i'nsertsfor' arch supports of W the second type, i. 'e. inserts comprising a rubber bag extending over the heeland the ball, the mid-.

die portlo n of the inner sidegof the. foot is lifted owing to the displacement of gas in the bag caused by the compression of the other, portions of theinsertfby the ball, the outer foot edge and relativelygreat, the pressure exerted by theball,

the outerfoot edge and the heel is not suificient, to press the opposite wall parts of the-rubber bag against each other. In suchjshoe inserts a gas-layer is therefore always present between the standing surface of the foot'and'the sole of the shoe, If, however, thegas pressure is relatively' small, the rubber bag, when, a person is standing on the same, will always be completely compressed at the portions in touch with theball,

the outer foot edge and the heel, and a gas 'cushion exists only on the middle portion 01' the inner volume of the gas space or gas chamber inthe rubher bag, andusing a small gas liquid, or other fluid fllling,"as "we'll as thin walls a pneumatic or hydraulic'shoe insert can be obtained that shall have substantlally'the shape of a vertical projection of the foot and that, when not compressed by the weight of the foot, is flat like an insole, thus the heel. This action'takes place independently of the value of the fluid-pressure existing in the rubberbag. If the gasor other fluid pressure is.

a consequence, the gas gives way by displacescribed, can occur."

taking up substantially no more room inthe shoe than an ordinary insole. The support for the foot I provided .by these prior-art insoles is quite defective. Among other defects, for example, undesirable gas cushions are formed, when compression occurs,,at the heel portion of the foot, along the outer edge of the foot, and at the regions of the toesparticularly the ball of the big toe. I An object of the present invention is to provide anew and improved insert or arch support 10 of the low-pressure types A iurtherobject is to provide an insertof the above-described character in'which the internal gas pressure isinitially or normallyv so low that normally, when not subjected to the pressure of 15 the foot, the insert occupies substantially no more space than an ordinary insole, so as not to support the foot when at rest, but the gas or other fluid contained in which'is entirely displaceable by the external pressure of the foot, bearing at the heel portion, the ball portion, and the outer ledge, 01! the foot, so as to cause the insert to become warped out of shape; resulting in the gas support, the arch of the foot.

Another object is to providean arch support 25 of the'above-described character having a con- .tinuous gas or' other fluid-containing chamber that shall provide uniform pressure, widely distributed o'ver the foot, not'only upon the middle portion of the longitudinal arch of the foot, but 30 also upon the inner portion of the arch, along the side. The external pressure of the heel portion, the ball portion and the outer edge of the foot compresses the gas contained in the rubber bag.

ment at desired points only, and there is no displacement at undesired points, with the result that no undesired 'gas cushions, as above de- Several embodiments of the invention are illustrated in the accompanying drawing in which: 7 t Fig. a top plan view of one embodiment adapted for the left foot,

' Fig. 2 is a sectionon I1 and Figi'3 a section'on II -II of Fig. 1.

Fig. 3a is a cross-section on'a line parallel to line II -II oi Fig. 1, the rubber bag being inserted in a shoe and compressed by the weight of the foot restingupon same.

Fig. 4 'is a bottom plan view of the insert according to Fig. 1. y, l

Fig. 5 shows'in section a mould for the production of an insert according to the invention and Fig. 6 in bottom plan view the top part of the mould.

As shown in Figs. 1 to 3, a rubber bag, constituted of an upper layer l a and a lower layer lb of plane sheets of rubber, forms a hollow pad the continuous or uniform gas-containing chamber 2 of which extends substantially under the whole heel portion, substantially under the whole ball portion, and under the outer edge, of the foot. Owing to the large size of the gas chamber 2 of the rubber bag, the small amount of its gas filling and the thin walls provided for by the rubber sheets la, lb, the rubber bag, in its uncompressed state, is not substantially bulkier than an insole. It will not, therefore, support the foot when at rest.

Although the shoe insert or arch support is shown in Figs. 1 to 3 in reduced scale, the insert is shown in Figs. 2 and 3, for clearness sake, in approximately its natural thickness. Owing to the small amount of gas pressure in the insert it may be that, if the upper layer consists'of an exceedingly thin rubber sheet la, shallow undulations will form on the surface of the insert when not subjected to the pressure of the foot. The function of the insert, however, is evidently not impaired thereby. The plan contours of the upper and lower layers la and lb correspond substantially to the perpendicular projection of the human foot, as illustrated more particularly in the drawing by A. It differs considerably from the shape of an insole of the boot or shoe, indicated in Fig. 1 by B. This contour B is strongly concave at the inneror right hand side, whereas the contour A extends at the inner orright hand side approximately in a straight line. If the ball, the outer foot edge and the heel press downward upon the rubber bag la, lb, the compressed gas is displaced from the complementary portions of the pad, in the direction of the arrows P, to the right and a portion of the same as a gas cushion, then occupies the area or region under the arch of the foot, atthe right of the contour line B, where the highest point of the foot arch is situated. The volume of the gas or other fluid in the chamber is substantially the same as and, in any event, not substantially greater than, the space under the arch of the foot. In the case of gas fillings, the volume of the gas is, when compressed, substantially the same as the space under the arch of the foot. In arch supports having a greater pressure or volume of gas, the heel portion, the ball portion 5 and the outer edge of the foot cannot displace all the gas from the complementary portions of the pad to the region of the arch, so that there is always present a layer of gas under other edge portions of the sole and under the heel portion and the ball portion of the foot. 'As liquids, however, are substantially incompressible, the volume of the liquid is substantially the same as the space under the arch of the foot.

The compressed gas cushion thus formed is situated to the left of the contour B the same distance as the foot arch is so situated. That portion of the insert, which is on the outer side of the contour of the insole B rests evidently upon the upper of the shoe as may be seen from Fig. 3a. The upper layer la and the lower layer lb are connected together along their edges to form a solid marginal zone or border 3 that extends throughout the whole periphery of the arch support, the shape and the dimensions of the arch support being such, and the marginal zone being layer lb at its points of attachment thereto. "convex'shape is caused by the internal gas presof such width that, under the pressure of the foot, the gas or other filling becomes displaced in one'direction only, towards the space below the arch, in such a manner as to cause the bag to press in an upward direction only towards the foot arch. The gas filling cannot, therefore, form, by displacement, undesirable secondary gas cushions along the circumference of the insert, or under the toes. The inner contour C of the solid marginal zone or border 3 lies outside the contour'B of the insole of the boot or shoe in the area or region only of the arch of the foot. The outline D of the standing surface of the foot is situated within the contour B of the insole. The inner contour C of the marginal zone or border 3 is disposed inside the outline D of the standing surface of the foot in the region of the heel, the outer foot edge and the ball, and also outside of said standing surface in the region of the longitudinal arch of the foot. As clearly shown in Fig. 1, theheel portion of the border 3 is pr'eferably of relatively great width, its width being shown greater than the width of the side portions of the border 3. This feature is important in order to prevent an undesired cushion of compressed fluid to be formed'behind the heel of the foot when the rubber bag is compressed by the weight of the foot.

The lower layer lb is substantially plane, whereas the portion of the .upper layer la between the marginal edges 3, as seenin Figs. 2'

and 3, is domed convexly over the lower layer lb and makes an acute angle with the lower The sum, not by previous molding, for the sheets la and lb, as before stated, are plane.

As shown in Fig. 4, the underside surface of the lower layer facing the insole of the shoe is provided with an anti-slip surface, which'may be produced by vulcanization, similarly to the surface of the outer sole of rubber shoes. As this anti-slip surface prevents the insert from slipping in the shoe, the insert may be made shorter than the length of the insole, i. e. the toe portion may be dispensed with.

The described inserts are suitable for weak and medium heavy casesof flat foot or spread foot.

The upper layer laof the described inserts has preferably a covering which is porous and, therefore, sweat absorbent, to promote ventilation.

If constituted, for example, of a suitable fabric,

' it may, together with the body of the insert, be

when under pressure.

The 'gas is introduced into the bag of the insert by means of a gas-developing substance accommodated between two mould halves} and 9 shown in Fig. 5, and the gas chamber of the insert is sealed. I

The mould half 8 has a cup-shaped cavity 8a which merges into a step 8b as shown also in Fig. 6. This. step serves to produce the above-mentioned marginal zone 3 of the insert. The lower half 9 of the mould has a cavity 9a. which, however, is'not cup-shaped, like the cavity 8a, but is plane. For manufacturing on a larger scale multiple moulds are employed, with the aid of which a great number of inserts can be produced at the same time. a

sealed gas orifice, a 'valve or the like, as it is desired that the gas be prevented from escaping,

a An important feature 01 the arch support according to the invention consists in that any still members whichmight affect the-natural walking-movement of the foot are dispensed with. It will be apparent that" the arch support, as

described and illustrated is extremely simple in construction and canbe manufactured at a-comparatively low'cost; v

While I have shown and described the preferred embodiments of my invention, it will be obvious that various changes in details oi construction and in the proportions may be resorted to for-successfully carrying my invention into practice without sacrificing any "of the novel features or departing from the scope of the ap pended claims.

. What I claim is:--

l. A pneumatic. shoe insert of the low-pressure ,type'comprising a'rubber bag Iconstltuted'of an upper layer and a lower layer each having substantially the shape of a vertical projection of the ioot'a'nd providing a continuous fluid-containing chamber extending substantially under the whole heelportlon, substantially under the whole ball portion, and under the outer edge, of thefoot, the

, layers being integrally connected together along their edges to form a solid marginal zone that extendsthroughout-the whole periphery of the insert, the pressure of the fluid in the chamber being normally so low that therubber bagis subthat," under the pressure of the foot, bearing at the heel portion, the ball portion and the outer edge, of the foot, all the -fluid in the chamber becomes displaced into a single fluid cushion in v the said space under the arch of the foot, thereby preventing the'i'ormation of fluid cushions elsewhere than in the said space under the arch oi. the foot, whereby the said single fluid cushion exerts pressure in an upward directiononly towards the arch of the foot.

2. A pneumatic shoe insert of the low-pressure type comprising a rubberbag constituted of an upper layer and a lower layer each having substantially theshape of a vertical projection of the foot and providing a continuous fluid-containing chamber extending substantially under the whole. heel portion, substantially under the whole ball portion, and under the outer edge, or

the foot, the layers being integrally connectedmtogether along their edges to form a solid marginal zone that extends throughout the whole periphery of the insert, the lower layer being substantially plane, the upper layer making an acute angle with the lower layer at its connection thereto alongthe inner edge of the marginal zone and being convexly curved above the lower layer, the pressure of thefluid in the chamber being normally so low that the rubber bag is substa-ntially flat when uncompressed so as to exert substantially ndpressure upon the foot when at rest, the volume or the fluid in the chamber being when compressed substantially'the same as the space under the arch of the foot, and the shape and the dimensions of the insert being suchpand the marginal zone being of such width, that, underthe pressure or. the foot, bearing at the-heel portion, the ball portion and the outer edge, otthe toot, all the fluid in the chamber becomes displaced into a single fluid cushion in the said space under the arch of the foot, thereby preventing the formation of fluid cushions elsewhere than in the said space under the arch of the foot, whereby the said single fluid cushion exerts pressure in an upward direction only towards the arch of the foot.

3. Shoe insert as claimed in claim 1 characterized in that the face of the lower layer facing the shoe has an anti-slipping profile.

4. Shoe insert as claimed in claim 1 characterized in that the upper layer is covered with a porous, absorbent material, said cover engaging with pocket-like extensions over the lower layer to permit an easy exchange of the porous, absorbent material.

5. A pneumatic shoe insert of the low-pressure type comprising a rubber bag having substantially the shape of a vertical projection of the foot and providing a continuous fluid-containing chamber extending substantially under the whole heel portion, substantially under the whole ball portion, and under the outer edge, of the foot, the bag having a solid marginal zone that extends throughout its whole periphery, the inner contour of the zone lying'outside of the contour of the insole only in the region of the longitudinal arch of the foot, the'pressure of the fluid in the chamber'be'ing normallyso low that the rubber bag is substantially flatwhen uncompressed so as to exert substantially no pressure upon the foot when at rest, the volume of the compressed fluid in the chamber being substantially the same as the space under the arch of the foot, and the shape and the dimensions of the insert being such, and the marginal zone being of such width, that, under the pressure of the foot, bearing at the heel portion, the ball portion and the outer edge, of the foot, all the fluid in the chamber becomes displaced into a single fluid cushion in the said space under the arch of the foot, thereby preventing the formation of fluid cushions elsewhere than in the said space under the arch of the foot, and whereby the said single fluid cushion exerts pressure in an upward direction only towards the arch of the foot. y

, 6. A pneumatic shoe insert of the low-pressure type comprising a rubber bag constituted of an upper layer and a lower layer each having substantially the shape of a vertical projection of the foot and providing a continuous fluid-containing chamber extending substantially under the whole heel portion, substantially under the whole ball portion, and under the outer edge, of the foot, the layers being integrally connected together along their edges to form a solid marginal zone that extends throughout the whole periphery of the insert, the edge of the marginal zone adjacent to the longitudinal arch of the foot being substantially rectilinear, the inner edge of the zone being disposed inside the contour of the under side of the foot in the region of the heel, the edge df the outer foot and the ball and outsideof the contour of the insole in the region of the longitudinal arch of the foot, the layers being shorter than the foot so as not to include a toe portion, the pressure of the fluid in the chamber being normally so low that the rubber bag is substantially flat when uncompressed so as to exert substantially no pressure upon the foot when at rest, the volume of the compressed fluid in the chamber being substantially the same as the space under the arch of the foot, and the shape and the dimensions 01 the insert being such, and the marginal zone being of such width, that, under the pressure of the foot,

fluid in the chamber becomes displaced into a 'single fluid cushion in the said space under the arch of thefoot, thereby preventing the formation of flui cushions elsewhere than in the said space under the arch of the foot, whereby the said single fluid cushion exerts pressure in an upward direction only towards the arch of the foot, the upper layer 'being provided with a cover of porous absorbent material, and the lower layer being provided with an anti-slip surface.

7. A pneumatic shoe insert of the low-pressure type comprising a rubber bag having substantially. the shape of a vertical projection of the foot and providing a continuous fluid-containing chamber extending substantially under the whole heel portion, substantially under the whole ball portion,

and under the outer edge, of the foot, the bag having a solid marginal zone that extends throughout its whole periphery, the inner contour of the zone lying outside of the contour of the insole only in the region of the longitudinal arch of the foot, the heel portion of the zone being of greater width than the side portions thereof, the pressure of the fluid in the chamber being normally so low that the rubber bag is substantially fiat when uncompressed so as tov exert substantially no pressure upon the foot when at rest, the volume of the compressed fluid in the chamber being substantially the same as the space under the arch of the foot, and the shape and the dimensions of the insert being such that, under the pressure of the foot, bearing at the heel portion, the ball portion and the outer edge, of the foot, substantially all the fluid in the chamber becomes displaced into a single fluid cushion in the said space under the arch of the foot, thereby preventing the formation of fluid cushions elsewhere than in the said space under the arch of the foot, and whereby the said single fluid cushion exerts pressure in an upward direction only towards the arch of the foot. v

8. A pneumatic shoe insert of the low-pressure type comprising a rubber bag constituted of an upper layer and a lower layer each having substantially the shape of a vertical projection of the foot and providing a continuous fluid-containing chamber extending substantially under the whole heel portion, substantially under the whole ball portion, and under the outer edge, of the foot, the layers being integrally connected together along their edges to form a solid marginalzone' that extends throughout the whole periphery of the insert, the said periphery being disposed outside of the contour of the insole in the region where the longitudlnal'arch of the foot is situated, the layers being shorter than the foot so as not to include a toe portion, the heel portion of the zone being of greater width than the side portions thereof, the inner edge of the zone being disposed outside of the contour of the insole in the'region of the longitudinal arch of the foot, the upper layer being provided with a cover of porous absorbent material, and the lower layer being provided with an anti-slip surface.

9. A pneumatic shoe insert of the low-pressure type comprising a rubber bag constituted of an upper layer and a lower layer each having substantially the shape of a vertical projection of the foot and providing a continuous gas-containing chamber extending substantially under thev whole heel portion, substantially under the whole ball portion, and under the outer edge, of the foot, the layers being integrally connected together along their edges to form a solid marginal zone that extends throughout the whole periphery of the insert, the pressure of the gas in the chamber being normally so low that the rubber bag is substantially flat when uncompressed so as to exert substantially no pressure upon the foot when at rest, the volume of the gas in the chamber when compressed being substantially the same as the space under the arch of the foot, and the shape and the dimensions of the insert being such, and the marginal zone being of such width, that, under the pressure of the foot, bearing at the heel portion, the ball portion and the outer edge, of the foot, all the gas in the chamber becomes displaced into a single gas cushion in the said space under the arch of the foot, thereby preventing the formationof gas cushions elsewhere than in the said space under the arch of the foot, whereby the said single gas cushion exerts pressure in an upward direction only towards the arch of the foot, the bag being unprovided with an orifice,and the gas being introduced into the chamber through the medium of a gas-developing substance introduced between the layers prior to connecting them together.

10. A pneumatic arch-supporting insert comprising a rubber bag constituted of an upper layer and a lower layer each having substantially the shape of a vertical projection of a human foot and providing a uniform gas-containing chamber extending under the heel and ball portion and under the outer edge of the foot, the pressure of the gas in the chamber being normally so lowthat the rubber bag is substantially flat when uncompressed so as to exert substantially no pressure upon the foot when at rest, the volume of the uncompressed gas being so small that when the rubber bag is compressed by'the foot the inner surfaces of the layers are pressed against each other at the heel and ball portion and under the outer edge of the foot and the volume of the compressed gas being sogreat that the arch of the foot is supported when the pressure of the .foot is applied to the heel and ball portion and the outer edge of the foot, the layers being integrally connected together along their circumference to form a solid marginal zone that extends throughout the whole circumference of the insert, the inner edge of said solid marginal zone lying within the outline of the insole in the heel and ball portion and along the outer edge of the foot and lying outside the outline of the insole in the region oflthe longitudinal arch only, the upper layer being provided with a cover of porous absorbent material, and the lower layer being provided with a friction profile on the shoe-contacting surface.

HANS VOGEL. 

